RAM Upgrade Question

Discussion in 'NZ Computing' started by JohnO, Mar 2, 2009.

  1. JohnO

    JohnO Guest

    Hi All,

    Need to upgrade a Dell Optiplex755 from 2Gb to 4Gb. It has 4 240 pin
    DIMM slots, and two are currently occupied by 1Gb modules.

    The crucial.com website recommends DDR2-667 PC5300 memory. However It
    seems that DDR2-800 PC6400 is actually cheaper. Can this be used
    instead? Any reason not to?

    JohnO, Mar 2, 2009
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  2. JohnO

    Gordon Guest


    Well assuming that the MB and the OS can take 4GB of RAM.
    Gordon, Mar 2, 2009
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  3. JohnO

    simonnz10 Guest

    It should be fine given that you're using what is generally regarded
    as a pretty good brand.
    simonnz10, Mar 2, 2009
  4. JohnO

    JohnO Guest

    Yep, WinXP so 4GB is supported and the mobo supports up to 8GB.
    JohnO, Mar 2, 2009
  5. JohnO

    ~misfit~ Guest

    WinXP 32 bit? My desktop machine has 4GB fitted but XP reports 3.25GB. It
    works fine though....
    ~misfit~, Mar 2, 2009
  6. JohnO

    Enkidu Guest

    The difference is probably the video card aperture. I theeenk that XP 64
    moves that above 4GB.


    Enkidu, Mar 2, 2009
  7. Yes, there needs to be room in the 32-bit address space for all the
    I/O addresses. 32 bits = 4 Gibytes of address space, so the RAM under
    the I/O addresses is unusable. Vista 32-bit is the same, as is Linux
    32-bit (but you can configure how much is used in Linux).
    Stephen Worthington, Mar 2, 2009
  8. In message <29a64027-32fb-4b70-8cef-
    If it's 32-bit Windows, it'll need PAE support to access more than about
    3GiB, which is not available in XP Home.
    Lawrence D'Oliveiro, Mar 2, 2009
  9. JohnO

    simonnz10 Guest

    Yup, good point. We probably should have asked for more information
    right at the start!
    simonnz10, Mar 2, 2009
  10. JohnO

    news2.thing Guest

    news2.thing, Mar 5, 2009
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